The present technology relates to a semiconductor device and to a method of manufacturing a semiconductor device.
A color image sensor such as a CCD color image sensor and a COMS color image sensor has included a color filter between a light-entrance section and a photoelectric conversion section. The color filter is formed by coating with, exposing, and developing a color resist containing a pigment or a dye of a necessary color by a photolithography technology.
However, since the color filter formed by the photolithography with the use of the color resist is weak against high heat, the color filter gets burned at around 300 deg C. Therefore, after the color filter is formed, a high-temperature process is not allowed to be used.
For example, a photoelectric conversion element section, a wiring section, an inorganic lens section, a passivation film, and the like in a typical structure of the CMOS color image sensor are sections for formation of which a high-temperature process is necessary. Therefore, it is necessary to form a color filter after the formation of the photoelectric conversion element section, the wiring section, the inorganic lens section, the passivation film, and the like. As a result, the color filter is formed in a layer above the foregoing sections.
In addition thereto, since the color filter formed by the photolithography with the use of the color resist has low light resistance, the color filter may be discolored after operation for a long time. Further, according to a size and an aggregation state of a coloring matter (a pigment or a dye) dispersed in the resist, a defect such as a minor black-dot defect may occur.
As technologies to resolve the foregoing disadvantages, Japanese Unexamined Patent Application Publication Nos. H04-73968 (JP H04-73968A) and 2000-347023 (JP 2000-347023A) have been disclosed.
JP H04-73968A discloses a technology for forming a colored glass to become a color filter film by a vapor-phase deposition method such as a low-pressure CVD method or a coating method with the use of alkoxysilane and organic metal. The colored glass contains silicon oxide as a main component, and includes a metal element such as Au, Cu, Se, Cd, Fe, Cr, and Co; or a compound such as an oxide, a sulfide, and a halide of any of these metal elements as a colorant.
JP 2000-347023A discloses a technology for doping an inorganic material film having a transparent inorganic oxide such as aluminum oxide as a main component with a predetermined dose amount of a transition metal by a sputtering method or a CVD method. As a doping transition metal, chromium for a red color filter, beryllium and silicon for a green filter, and titanium and iron for a blue color filter are exemplified.